Topic 17 - Biological Diversity Flashcards
Alternation of generations
A life cycle involving alternation of a multicellular haploid stage (gametophyte) with a multicellular diploid stage (sporophyte). Occurs in most plants and some protists.
Animals
Members of a major lineage of eukaryotes (Animalia) which typically have a complex, large, multicellular body, eat other organisms, and are mobile.
Archaea
One of the three taxonomic domains of life consisting of unicellular prokaryotes distinguished by cell walls made of certain polysaccharides not found in bacterial or eukaryotic cell walls. Plasma membrane composed of unique isoprene-containing phospholipids and ribosomes and RNA polymerase similar to those of Eukaryotes.
Autotroph
Any organism that can synthesize reduced organic compounds from simple inorganic sources such as CO2 or CH4. Associated mostly with plants, but also with some bacteria and archaea. Also called primary producer.
Bacteria
One of the three taxonomic domains of life consisting of unicellular prokaryotes distinguished by cell walls composed largely of peptidoglycan, plasma membrane similar to those of eukaryotic cells, and ribosomes and RNA polymerase that differ from those in archaeans.
Cells
A highly organized compartment bounded by a thin, flexible structure (plasma membrane) and containing concentrated chemicals in an aqueous solution. The basic structural and functional unit of all organisms. Contains DNA with information which allows them to self-replicate and respond to environmental conditions, maintaining homeostasis.
Chemolithotroph
An organism that produces ATP by oxidizing inorganic molecules with high potential energy such as ammonia (NH3) or methane (CH4).
Chemoorganotroph
An organism that produces ATP by oxidizing organic molecules with high potential energy such as sugars.
Diplontic
Lifecycle in which the organism exists is the diploid form. It is observed mostly in animals. Haploid cells appear only briefly, as gametes.
Endosymbiosis
The theory that mitochondria and chloroplasts evolved from prokaryotes that were engulfed by host cells and took up a symbiotic existence within those cells. Some evidence is that both these organelles contain their own circular DNA, their own ribosomes (similar to bacterial ribosomes), the sequences of their proteins are similar to those of bacterial proteins, and both have double membranes. In addition, both organelles reproduce by fission, like bacteria.
Eukaryote
A member of the domain Eukarya; an organism whose cells contain a nucleus, numerous membrane-bound organelles, and an extensive cytoskeleton. Maybe unicellular or multicellular.
Fungi
A lineage of Eukaryotes that typically have a filamentous body (mycelium) and obtain nutrients by absorption. They have chitin cell walls.
Haplontic
Lifecycle in which the organism exist in the haploid form, with a diploid zygote being formed only briefly.
Heterotroph
An organism that cannot synthesize reduced organic compounds from inorganic sources and that must obtain them by eating other organisms. Some bacteria, some archaea and virtually all fungi and animals are heterotrophic. Also called consumer.
Obligate intracellular parasite
Organism that cannot reproduce outside their host cell, meaning that the parasite’s reproduction is entirely reliant on intracellular resources. Can also apply to viruses.
